The laying of mines in sea lanes and harbors can efficiently restrict and control hostile marine traffic during wartime. At the outbreak of hostilities, it may be very important to quickly secure control of ports, approach channels, and sea lanes of communication. This may require the use of craft of opportunity to reinforce and supplement a navy's fleet of regular minelaying platforms. A craft of opportunity (hereinafter referred to as "ship") can be any ship whose displacement permits it to carry mines in some quantity--that requirement being satisfied, a craft of opportunity can be any ship, military or civilian, slow or fast, large or small, with or without, or with very limited deck space available for the stowage and handling of mines.
Sea mines are quite heavy--some exceed 2,000 lb in weight--and they are typically configured like aircraft bombs. Such massive, rounded devices are quite difficult to handle on an unstable, rolling ship deck, especially in high seas. For safety reasons it has therefore been found desirable to mechanize the mine handling and drop. Minelaying rail systems, in which mines are cradled on wheeled undercarriages that roll in tracks mounted on the deck, have been employed. See. U.S. Pat. No. 1,183,695. Such systems succeeded in reducing the amount of manhandling required to lay the mines but were not altogether successful solutions: Slow and complicated tie-down systems were required to cradle and stabilize the mines in high sea states; furthermore, the high tie-down forces increased friction, requiring high forces to move the mines when fully secured.
Moreover, the minelaying systems of the prior art could not be easily adapted to different ships, especially to ships without ample deck space. They could not automatically release mines at short intervals at both low and high ship speeds, especially in rough sea states of, e.g., 3 through 5. They generally could not accept aircraft configured mines without modification to or special equipment for the mine. Furthermore, the minelaying systems of the prior art generally did not positively secure the mines from single-point loading until release, which would minimize the hazard to human loaders and operators.